MAKING AN EW BACKPLATE FROM A MYFORD BLANK
I HAD SUSPECTED THAT THE EARLIER MYFORD BACKPLATE COULD BE MODIFIED TO CREATE AN EW ONE AS IT HAD THE SAME THREAD DIMENSIONS BUT THE REGISTER DIAMETER WAS SLIGHTLY LARGER. I TRIED TO FIND A DRAWING ON THE NET SO THAT I COULD CHECK THIS OUT BUT WITH NO LUCK.
RDG TOOLS ADVERTISE THIS MYFORD BACKPLATE AND ALTHOUGH I HAD PROBLEMS WITH THE QUALITY OF THEIR PRODUCTS SOME YEARS AGO, DECIDED TO OBTAIN ONE TO SEE IF IT WAS OF THE REQUIRED QUALITY AND IF IT COULD BE MODIFIED TO SUIT THE EW.
THE BACKPLATE HAD OBVIOUSLY BEEN MACHINED ON A CNC MACHINE AND THE APPEARANCE WAS PLEASING WITH A GOOD SURFACE FINISH. HOWEVER WHEN I TRIED TO SCREW IT ONTO THE EW SPINDLE IT WAS RATHER TIGHT, TOO TIGHT TO SCREW ALL THE WAY ON. I CHECKED THE DIAMETER OF THE REGISTER AND IT WAS ON THE UPPER LIMIT OF PLUSS ONE THOU, SO THAT WAS GOOD ENOUGH. THEN I CHECKED TO SEE IF THE ID AND OD WERE CONCENTRIC AND THEY WERE. THIS WAS GOOD AS I COULD USE THE OD TO CENTRE THE BLANK IN THE 4 JAW CHUCK.
I DREW UP A PLAN TO SEE HOW THE CONVERSION COULD BE CARRIED OUT. IN FACT IT`S VERY EASY AND CAN ALL BE DONE ON THE EW. DRAWINGS ARE SUPPOSED TO MAKE THINGS CLEAR BUT I CAN SEE THAT THE ABOVE DOES NOT CLARIFY THE DETAILS AS WELL AS I WOULD LIKE.
THE BLANK HAS TO BE SHORTENED AT EITHER END AND AN INSERT PRESSED INTO THE REGISTER TO MAKE IT FIT ON THE EW SPINDLE.
THE BLANK HAS TO BE SHORTENED AT EITHER END AND AN INSERT PRESSED INTO THE REGISTER TO MAKE IT FIT ON THE EW SPINDLE.
ABOVE LEFT, I CENTRED THE BLANK IN THE 4 JAW AND USING THE INTERMEDIATE TAP BACKED UP BY A CENTRE IN THE TAILSTOCK CLEANED OUT THE THREAD WHICH WAS BEAUTIFULLY CUT BUT SLIGHTLY UNDERSIZED, SO IT WOULD FIT ON THE EW SPINDLE. IT`S BETTER TO HAVE IT UNDERSIZED AS THE QUALITY HSS DORMER TAP WILL CUT AN ACCURATE THREAD TO ENSURE THE BEST POSSIBLE FIT ON THE SPINDLE. ON THE RIGHT HAND IMAGE, I`M ROUGHING OUT THE INSERT TO BE A PRESS FIT IN THE BLANK, LEAVING SOME EXTRA MATERIAL IN THE LENGTH AND BORE TO BE FINISH MACHINED IN SITU.
ABOVE LEFT, THE INSERT PRESSED INTO THE BLANK, THEN IN THE CENTRE IMAGE THE BLANK SET UP IN THE 4 JAW AGAIN AND BORED OUT TO SIZE. THE RIGHT HAND IMAGE SHOWING THAT THE RUN OUT ON THE OD IS LESS THAN 1 THOU.
AT THIS STAGE I`VE NOT MACHINED UP THE FRONT FACE AND WILL LEAVE THIS UNTIL I NEED TO USE IT. IT MIGHT BE A GOOD IDEA IF YOU LEAVE THE THICKNESS SLIGHTLY OVERSIZE SO THAT IF YOU ACCIDENTALLY MACHINE THE CHUCK REGISTER UNDERSIZE YOU HAVE ENOUGH MATERIAL TO RE MACHINE IT AGAIN. ANOTHER IDEA WOULD BE TO LEAVE THE THICNESS AS IT IS AND BORE OUT THE CENTRE TO EQUAL THE CHUCK ID SO THAT A LONGER LENGTH OF WORK CAN BE ACCOMMODATED FOR LARGER DIAMETERS. ALSO IF YOU LEAVE THE BLANK OD AS IT IS THEN THE BACKPLATE COULD BE RE USED FOR ANOTHER CHUCK.
THIS WAS IN INTERESTING EXERCISE THAT PROVED TO BE A POSSIBLE ANSWER FOR EW OWNERS TO MAKE THEIR OWN BACKPLATES. THIS TIME EVERYTHING WENT TO PLAN BUT DON`T BLAME ME IF YOU FOLLOW THIS ROUTE AND FIND THAT THE BLANK THAT IS SUPPLIED DOES NOT COME UP TO AN ACCEPTABLE STANDARD, HOWEVER THIS TIME IT WAS A COMPLETE SUCCSESS.
AT THIS STAGE I`VE NOT MACHINED UP THE FRONT FACE AND WILL LEAVE THIS UNTIL I NEED TO USE IT. IT MIGHT BE A GOOD IDEA IF YOU LEAVE THE THICKNESS SLIGHTLY OVERSIZE SO THAT IF YOU ACCIDENTALLY MACHINE THE CHUCK REGISTER UNDERSIZE YOU HAVE ENOUGH MATERIAL TO RE MACHINE IT AGAIN. ANOTHER IDEA WOULD BE TO LEAVE THE THICNESS AS IT IS AND BORE OUT THE CENTRE TO EQUAL THE CHUCK ID SO THAT A LONGER LENGTH OF WORK CAN BE ACCOMMODATED FOR LARGER DIAMETERS. ALSO IF YOU LEAVE THE BLANK OD AS IT IS THEN THE BACKPLATE COULD BE RE USED FOR ANOTHER CHUCK.
THIS WAS IN INTERESTING EXERCISE THAT PROVED TO BE A POSSIBLE ANSWER FOR EW OWNERS TO MAKE THEIR OWN BACKPLATES. THIS TIME EVERYTHING WENT TO PLAN BUT DON`T BLAME ME IF YOU FOLLOW THIS ROUTE AND FIND THAT THE BLANK THAT IS SUPPLIED DOES NOT COME UP TO AN ACCEPTABLE STANDARD, HOWEVER THIS TIME IT WAS A COMPLETE SUCCSESS.
THE ECONOMICS
SO HOW MUCH WILL THIS FINISHED BLANK COST?
THOSE LIVING IN THE UK CAN BUY IT FOR A TOTAL COST OF 37 GBP. THEN THERE WILL BE THE COST OF A QUALITY TAP FROM TRACY TOOLS TO CLEAN OUT THE THREAD, YOU COULD USE A HAND CHASER BUT IT`S TOO EASY TO CUT THE THREAD OVERSIZE. A DORMER HSS TAP WILL COST 35 GBP PLUS POSTAGE. THIS IS A REASONABLE PRICE AND THE TAP CAN BE USED AGAIN.
THOSE LIVING IN NORWAY WILL HAVE TO PAY 570 NOK FOR THE BLANK WHICH INCLUDES NORWEGIAN VAT. A DORMER TAP FROM TRACY TOOLS WILL COST 35 GBP PLUS POSTAGE TO NORWAY ABOUT 15 GBP.
THIS IS A SUGGESTION FOR THOSE THAT DON`T WANT TO BUY IN THE MATERIAL, MACHINE AND DO THE SCREWCUTTING ON THE BACKPLATES.
IN THE FUTURE I WILL CREATE MY BACKPLATES THIS WAY AS IT SAVES TIME WHEN THERE ARE SO MANY OTHER MORE IMPORTANT THINGS THAT NEED TO BE DONE
THOSE LIVING IN THE UK CAN BUY IT FOR A TOTAL COST OF 37 GBP. THEN THERE WILL BE THE COST OF A QUALITY TAP FROM TRACY TOOLS TO CLEAN OUT THE THREAD, YOU COULD USE A HAND CHASER BUT IT`S TOO EASY TO CUT THE THREAD OVERSIZE. A DORMER HSS TAP WILL COST 35 GBP PLUS POSTAGE. THIS IS A REASONABLE PRICE AND THE TAP CAN BE USED AGAIN.
THOSE LIVING IN NORWAY WILL HAVE TO PAY 570 NOK FOR THE BLANK WHICH INCLUDES NORWEGIAN VAT. A DORMER TAP FROM TRACY TOOLS WILL COST 35 GBP PLUS POSTAGE TO NORWAY ABOUT 15 GBP.
THIS IS A SUGGESTION FOR THOSE THAT DON`T WANT TO BUY IN THE MATERIAL, MACHINE AND DO THE SCREWCUTTING ON THE BACKPLATES.
IN THE FUTURE I WILL CREATE MY BACKPLATES THIS WAY AS IT SAVES TIME WHEN THERE ARE SO MANY OTHER MORE IMPORTANT THINGS THAT NEED TO BE DONE